Vortex damping wiper blade

ABSTRACT

A windshield wiper blade cover and a wiper blade. The windshield wiper blade cover being capable of being disposed on the top side of a wiper blade. The cover has a base portion having a height and a raised portion having a height, the height of the raised portion is greater than the height of the base portion, and the height of the raised portion gradually decreases as the raised portion approaches the outer ends of the cover.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/453,601 filed on Apr. 23, 2012, which claims the benefit of U.S.Provisional Application No. 61/477,908 filed Apr. 21, 2011, the entirecontents of which are hereby incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

This invention relates to the field of windshield wiper blades.

BACKGROUND

Typical wiper blades used on vehicles are plagued with numerouspersistent drawbacks. Among these drawbacks are two common andinterrelated drawbacks are of interest. The first such drawback is wiperblade separation from the surface of the windshield. The second suchdrawback is wind noise generated by the air moving over the wiper bladeas a vehicle travels at speed.

One persistent cause of wiper blade separation from the windshield isthe lack of sufficient downward force from the wiper blade onto thewindshield. A major contributing factor to insufficient downward forceinvolves wind lift. That is, wind passing over the windshield creates a“lifting” force which may cause the wiper blade to lose partial orcomplete contact with the surface of the windshield, and thus result inuneven or inconsistent clearing of water off the windshield. The windlift problem has been known in the wiper field for decades, and manyattempts have been made to resolve it. For example, see U.S. Pat. Nos.3,056,991, 3,317,945, 3,879,793, 3,942,212, 6,292,974, 6,944,905, whichare incorporated herein by reference in their entirety.

One common solution to the wind lift problem is to add a wind deflectionstructure, or spoiler, to the top of the wiper blade. On a beam blade, aspoiler is generally affixed to the top of the wiper blade, therebysubstantially increasing the height and outer cross-section of the wiperblade overall, and increasing the need for an anti wind-lift structure.Moreover, for cost and ease of manufacture reasons, these spoilers havea uniform cross-sectional profile across the entire length, orsubstantially the entire length of the wiper blade structure. U.S. Pat.No. 6,944,905, for instance describes a uniformly shaped spoiler, exceptfor the end sections, in which a wall and abrupt corner are used at theend of the wind deflection strip, slanting down to the end of the blade.

Another problem associated with wiper blades is that wind noisegenerated as a wiper blade is used while the vehicle travels at higherspeeds. In general, undesirable wind noise from wiper blades originatesin part from air vortices formed by wind contacting a wiper blade. Innormal operation, as wind flows over a wiper blade, an air vortex formsbehind the wiper blade, that is, on the leeward side of the wiper blade.Moreover, the size of the vortex is proportional to the height of thewiper blade, from its contact point with the windshield to the top ofits cross-sectional profile. Thus, a wiper blade with a larger winddeflection structure generates a larger vortex, and therefore morenoise.

Generally, wind noise is created as a wiper blade enters a slip streamof wind above the windshield. The wind noise created from wiper bladesencountering the slip stream is distracting and makes for a lesscomfortable overall driving experience. Reduction of such wind noise istherefore a constant concern associated with wiper blade design.

Wiper blade separation from the windshield is a primary concern in wiperblade design because of potential safety hazards that can arise out ofpoor wiping performance. However, a wiper blade designer should alsoattempt to minimize the amount of noise caused by the design of thewiper blade in order to allow for a more comfortable driving experiencefor the driver of the car on which the wiper blades are installed. Wiperblades currently used in the art do not adequately present a solutionthat addresses the wind lift problem while minimizing the amount ofnoise generated by the wiper blade.

BRIEF SUMMARY

The foregoing problems of prior wiper blades are resolved or at leastsubstantially reduced and a technical advance is achieved in alow-profile wiper blade that reduces or eliminates wind-lift whiledamping wind noise. The present invention achieves this through agradually decreasing-height cover attached to the surface of a wiperblade.

In certain embodiments, the invention comprises a wiper blade having abeam with two ends, two longitudinal sides, a top side and a bottomside. The wiper blade further has a central bridge disposed on the topside of the beam, a wiper strip disposed on the bottom side of the beamand a cover having two longitudinal sides, two outer ends and a topsurface. The cover may be disposed on the top side of the beam, and thetop surface of the cover has a base portion having a height and a raisedportion having a height, wherein the height of the raised portion isgreater than the height of the base portion and the height of the raisedportion gradually decreases as the raised portion approaches the outerends of the cover.

Certain embodiments of the invention are directed to a wiper blade covercomprising two longitudinal sides, two outer ends and a top surface,wherein the cover is capable of being disposed on the top side of abeam. The top surface of the wiper blade cover may have a base portionhaving a height and a raised portion having a height, where the heightof the raised portion is greater than the height of the base portion andthe height of the raised portion gradually decreases as the raisedportion approaches the outer ends of the cover.

Certain embodiments of the invention are directed to a wiper bladecomprising a beam having two ends, a central bridge disposed on thebeam, and a cover, wherein the cover has a spoiler that tapers from ahighest point in the vicinity of the central bridge to a lowest point inthe vicinity of the ends of the beam.

In some embodiments where the raised portion of the cover may optionallyembody a wind deflection structure that gradually recedes along thelength of the cover as it approaches the ends of the wiper blade, suchthat the tip of the wind deflection structure is either at or near thesurface of the base of the cover at the ends of the wiper blade, or hascompletely receded into the base of the cover before reaching the end ofthe wiper blade.

In embodiments where the raised portion of the cover of the beam bladedoes not embody a spoiler, the cover the raised portion that graduallyrecedes along the length of the cover as it approaches the ends of thewiper blade such that the raised portion of the cover is at or near thesurface of the base of the cover, at the ends of the wiper blade, or hascompletely receded into the base of the cover before reaching the end ofthe wiper blade. In such embodiments, the raised portion of the cover ispreferably curved in order to minimize the effect of the wind on thatraised portion.

By gradually receding the top of the cover, whether it is a winddeflection structure or merely a raised portion, along the length of thecover as it approaches the ends of the wiper blade, the vortex formedbehind the wiper blade relative to the direction of the oncoming wind isdecreased along the length of the wiper blade, and approaching its ends.The decreasing profile of the cover reduces and/or dissipates thevortex, thereby reducing or eliminating the audible noise (to the driverof the vehicle) caused by the vortex.

It is notable that the portion(s) of the cover nearest the middle of thewiper blade need not be the “tallest” portions of the wiper blade. Also,the cover may be one piece, may be two pieces on either side of aconnection device or mounting base attached at or near the middle of thebeam, or may be made of multiple parts. In embodiments having two (ormore) parts of the cover, there may be a cap, or caps, covering gaps inthe cover. For instance, in an embodiment having two covers, one foreach side of the wiper blade, there may be a cap which covers the innerends of the two covers, and the connection device or mounting base.

Exemplary embodiments are attached hereto as examples of the invention,both with a wind deflection structure, and with a raised portion of thecover.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a first embodiment of a slimprofile wiper blade of the present invention.

FIG. 2 illustrates a front view of a first embodiment of a slim profilewiper blade of the present invention.

FIG. 3 illustrates a bottom view of a first embodiment of a slim profilewiper blade of the present invention.

FIG. 4 illustrates a right end view of a first embodiment of a slimprofile wiper blade of the present invention.

FIG. 5 illustrates a left end view of a first embodiment of a slimprofile wiper blade of the present invention.

FIG. 6 illustrates a perspective view of a second embodiment of a slimprofile wiper blade of the present invention.

FIG. 7 illustrates a right end view of a second embodiment of a slimprofile wiper blade of the present invention.

FIG. 8 illustrates a front view of a second embodiment of a slim profilewiper blade of the present invention.

FIG. 9 illustrates a top view of a second embodiment of a slim profilewiper blade of the present invention.

FIG. 10 illustrates a bottom view of a second embodiment of a slimprofile wiper blade of the present invention.

FIG. 11 illustrates a perspective view of a third embodiment of theinvention.

FIG. 12 illustrates perspective view of a fourth embodiment of theinvention.

As is apparent to persons of skill in the art FIGS. 1-12 depict thewiper blades as being flat for convenience and to show the relativerelationships between the various parts. However, embodiments of theinvention are preferably curved to better perform and contour to theshape of the spherical windshields found on motor vehicles. Accordingly,the scope of the invention is not intended to be limited to flat wiperblades and is intended to include curved embodiments within its scope.

DETAILED DESCRIPTION

The following detailed description and the appended drawings describeand illustrate exemplary embodiments of the invention solely for thepurpose of enabling one of ordinary skill in the relevant art to makeand use the invention. As such, the detailed description andillustration of these embodiments are purely exemplary in nature and arein no way intended to limit the scope of the invention, or itsprotection, in any manner. The embodiments discussed below are describedin sufficient detail to enable those skilled in the art to practice thesubject matter disclosed herein. It is to be understood that theembodiments may be combined, or that other embodiments may be utilized,and that structural and logical variations may be made without departingfrom the scope of the subject matter disclosed. Accordingly, referencesto any particular embodiment are not intended to be interpreted asexcluding the existence of additional embodiments that also incorporatethe recited features. It should also be understood that the drawings arenot to scale and in certain instances details have been omitted, whichare not necessary for an understanding of the present invention, such asconventional details of fabrication and assembly.

In certain embodiments, the invention comprises a wiper blade having abeam with two ends, two longitudinal sides, a top side and a bottomside. The wiper blade further has a central bridge disposed on the topside of the beam, a wiper strip disposed on the bottom side of the beamand a cover having two longitudinal sides, two outer ends and a topsurface. The cover may be disposed on the top side of the beam, and thetop surface of the cover has a base portion having a height and a raisedportion having a height, wherein the height of the raised portion isgreater than the height of the base portion and the height of the raisedportion gradually decreases as the raised portion approaches the outerends of the cover.

In certain embodiments of the invention, the wiper blade may furtherhave a raised portion that forms a wind deflection structure having agenerally triangular shape when viewed in cross section. In certainembodiments of the invention, the cover of the wiper blade may besymmetric in shape across a plane that is transverse to the twolongitudinal sides of the cover. In certain embodiments of the inventionthe cover of the wiper blade may be symmetric in shape across a planethat extends vertically through a longitudinal axis of the cover.

In certain embodiments of the invention, the raised portion of the wiperblade may have an apex that merges with the base portion before theouter ends of the cover. In certain embodiments of the invention, thecover of the wiper blade may be provided with two claws that run alongthe two longitudinal sides of the cover, wherein the longitudinal sidesof the beam are disposed in the two claws. In some such embodiments, theclaws may end in the vicinity of the outer ends of the cover, and theouter ends of the cover may be provided with a structure that securesthe ends of the beam.

In certain embodiments of the invention, the cover of the wiper blademay be a unitary structure and may be provided with a hole toaccommodate the central bridge of the wiper blade. In other embodimentsof the invention, the cover of the wiper blade may comprises twosections, where each section has an inner end and a gap is providedbetween the inner ends of the two sections to accommodate the centralbridge. In some such embodiments, the wiper blade may have a cap thatcovers the gap and the inner ends of the two sections of the cover.

Certain embodiments of the invention are directed to a wiper blade covercomprising two longitudinal sides, two outer ends and a top surface,wherein the cover is capable of being disposed on the top side of abeam. The top surface of the wiper blade cover may have a base portionhaving a height and a raised portion having a height, where the heightof the raised portion is greater than the height of the base portion andthe height of the raised portion gradually decreases as the raisedportion approaches the outer ends of the cover.

In certain embodiments of the invention, the raised portion of the wiperblade cover forms a wind deflection structure having a generallytriangular shape when viewed in cross-section. In certain embodiments ofthe invention the wiper blade cover is symmetric in shape across a planethat is transverse to the two longitudinal sides of the cover. Incertain embodiments of the invention, the raised portion of the wiperblade cover may have an apex that merges with the base portion beforethe outer ends of the cover.

In certain embodiments of the invention, the wiper blade cover may beprovided with two claws that run along the two longitudinal sides of thecover, wherein the claws are capable of receiving the longitudinal sidesof a beam. In some such embodiments, the claws of the wiper blade covermay end in the vicinity of the outer ends of the cover, and the outerends of the cover may be provided with a structure capable of securingthe ends of the beam.

In certain embodiments of the invention, the wiper blade cover is aunitary structure and is provided with a hole to accommodate the centralbridge of the wiper blade. In other embodiments of the invention, thewiper blade cover comprises two sections, each having an inner end, anda gap is provided between the inner ends of the two sections in order toaccommodate a central bridge of a wiper blade. In some such embodiments,the wiper blade cover may further be provided with a cap that covers thegap and the inner ends of the two sections of the wiper blade cover.

Certain embodiments of the invention are directed to a wiper bladecomprising a beam having two ends, a central bridge disposed on thebeam, and a cover, wherein the cover has a spoiler that tapers from ahighest point in the vicinity of the central bridge to a lowest point inthe vicinity of the ends of the beam.

Referring to the drawings in general, an elongate, wiper blade 10 may beslender and includes a beam (or support element) 80, a central bridge(or mounting base) 44, a cover 22, a front edge 32, a rear edge 34,opposing ends 26 having front edge 32 and rear edge 34 therebetween, awiper strip 48 and either a tapered spoiler 60 or a tapered raisedportion 61. The wiper blade 10 may optionally further comprise aconnector 14. As best shown in FIG. 3, wiper blade 10 may have an outeredge or perimeter 56 formed by front edge 32, left end 40, rear edge 34,and right end 36. The front edge 32 and rear edge 34 may also be calledthe longitudinal sides of the wiper blade. The perimeter 56 is generallydefined by a curvilinear cover 22, having either a tapered spoiler 60 ora tapered raised portion 61. The tapered spoiler 60 or tapered raisedportion 61 constitute a highly effective means for damping air vortices.Connector 14, which is removably attached to the central bridge 44,secures the wiper blade 10 to a driver arm (not shown) that actuates thewiper blade 10. As is well known in the art, different kinds ofconnectors may be used to connect the wiper blade 10 to different wiperarms, or multi-arm connectors can be used to connect to various types ofarms. Additionally, the central bridge 44 may be designed to connect toa particular type (or types) of wiper arm(s), thereby making a connector14 unnecessary.

FIGS. 1-5 depict a first embodiment of the wiper blade 10 having a cover22 with a top surface 76 with a pedestal or base region that supportsand defines the outer boundary of the a raised portion that embodies atapered spoiler 60, having a generally triangular shape when viewed incross-section (FIGS. 4 & 5). The tapered spoiler 60 provides acurvilinear outer surface 68, best shown in FIG. 4. The tapered spoiler60 provides a centrally elevated area most clearly defined at apex 64(FIG. 4), which extends along axis 52 (FIG. 1). In use, the taperedspoiler 60 acts as a means for reducing wind vortices because it allowswind to pass over it with minimal or no noise effect. Specifically, thenovel low-profile, longitudinally tapered design of tapered spoiler 60provides minimized or negligible vortex at the leeward side of wiperblade 10. The tapering of the tapered spoiler 60 is gradual, andtapering downwards towards the ends of the wiper blade 36, 40. Indeed,as shown in FIGS. 1 & 2, the height of the tapered spoiler 60 may recedeinto the height of the base portion of the top surface of the cover 22in the vicinity of (either before the end of or at the end of) the outerends of the cover such that the tapered spoiler 60 merges with the baseportion. Alternatively, as shown in FIG. 12, the height of the taperedspoiler may still be greater than the height of the base portion of thetop surface of the cover at the ends of the cover 22.

The wiper blade 10 may also optionally further comprise a covering cap18, which covers the gaps between the cover and the central bridge 44.As shown in FIGS. 1-5, the cover 22 may comprise two sections, eachhaving an inner end in the vicinity of the central bridge 44. As bestseen in FIG. 3, the sections of the cover 22 thereby have a gap betweentheir respective inner ends which accommodates the central bridge. Asshown in FIG. 1, the covering cap 18 covers this gap and the inner endsof the cover sections, and is provided with a hole to accommodate thecentral bridge 44. This covering cap may also be vertically extended tocover the connection area between wiper arm, the connector 14 (if one isused), and the central bridge 44 (not shown).

Alternatively, as shown in FIGS. 11 and 12, the cover may also be asingle piece, shaped to cover the central bridge, thereby obviating theneed for a covering cap 18. In such embodiments, the cover 22 isprovided with a hole which can accommodate the central bridge. 44. Asshown in FIGS. 11 and 12, the portion of cover 22 surrounding thecentral bridge 44 may cover only the connection between the beam 80 andthe central bridge 44, leaving the connecting area between the centralbridge 44, wiper arm and connector 14 (if any) uncovered. Alternatively,the cover 22 may extend vertically to also cover the connection areabetween the wiper arm, connector 14 (if one is used) and the centralbridge 44 (not shown).

As shown in FIGS. 1 and 11, the tapered spoiler 60 may be located in thecenter of the cover, or towards the rear edge of the cover 22, and maybe symmetric across the plane extending vertically through the axis 52.Alternatively, as shown in FIG. 12, the apex 64 of the tapered spoiler61 may be nearer to one longitudinal side (such as the rear edge 34)than to the other. As shown in FIGS. 2, 11 and 12 the cover may also besymmetric across the plane that is transverse to the longitudinal sidesand axis 52.

FIGS. 6-10 depict a second preferred embodiment of the wiper blade 10having an upper surface 76 with a pedestal or base region that supportsand defines the outer boundary of the tapered raised portion 61. As bestillustrated in FIGS. 6 and 8, tapered raised portion 61 provides agradual taper that extends nearly the entire length between right end 36and left end 40. As detailed in connection with the first preferredembodiment, the novel low-profile, slim design of tapered raised portion61 provides minimized or negligible vortex at the leeward side of wiperblade 10. Further, the gradual taper of the tapered raised portion 61,which is even less pronounced than the taper of the first preferredembodiment described above, provides exceptionally low drag anddrastically limits vortex formation on the leeward edge. As best shownin FIGS. 8-10, the second preferred embodiment of the wiper blade 10includes partially blunted ends 36 and 40. Because this second-preferredembodiment does not have a spoiler, or wind deflector, such embodimentspreferably maintain a low profile. The distance from the bottom of thewiper strip to the highest point of the raised portion is preferablyless than one inch, and is more preferably a half-inch or less.

As discussed above in connection with the first embodiment of theinvention, in certain embodiments, the cover 22 may comprise twosections, each having inner ends in the vicinity of the central bridge44 of the wiper blade, such that there is a gap between the inner endsof the cover sections which accommodates the central bridge 44. In suchembodiments the cover 22 may be provided with a covering cap 18 whichcovers that gap and the inner ends of the cover sections. The coveringcap is provided with a hole to receive the central bridge, and mayoptionally be extended upwards to also cover the connection areaincluding the central bridge 44, connector 14 (if any) and the wiperarm. Alternatively, the cover 22 may be embodied as a unitary structure,obviating the need for a covering cap.

As also discussed above in connection with the first embodiment, theheight of the tapered raised portion 61 may recede into the height ofthe base portion of the top surface of the cover 22 in the vicinity of(either before the end of or at the end of) the outer ends of the coversuch that the tapered raised portion 61 merges with the base portion.Alternatively, the height of the tapered raised portion 61 may still begreater than the height of the base portion of the top surface of thecover at the ends of the cover 22.

As shown in FIGS. 3 and 10, the bottom of the beam 80 may receive andsecure the wiper strip 48. The beam 80 is attached to the central bridge44 at joints 88. These joints may be crimped or welded to the beam,shaped to fit notches in the beam or attached via any other methodcurrently known in the art. It will also be apparent to one of skill inthe art that the central bridge 44 is preferably in the middle of thebeam 80, but may be located anywhere along the length of the beam 80.

The beam 80 is preferably made from a spring metal, and is generallyrectangular, but may taper. The beam 80 may comprise a single strip, ormay be two strips that are held together by the central bridge 44, orother bridging devices (not shown) on the ends, or along the length ofthe beam 80. If a single beam is used, it may be “U” or “0”-shaped,having a groove running longitudinally along the middle of the beam,such that a wiper strip 48 can be slid in between the groove between thesides of the “U” or “0”. Alternatively, where the beam 80 may have nosuch groove, and the wiper strip may be secured to the bottom of thebeam 80 by glue or clips, or any other methods currently known in theart for securing the wiper strip to the beam 80.

Cover 22, in turn is fitted or seated on and around the perimeter ofbeam 80. The cover 22 may be fitted or seated to the ends of the beam 80by means of detents, securing cavities 28, claws, or other methodscurrently known in the art. As shown in FIGS. 3 and 10, the cover 22 maybe provided with claws which run along the longitudinal sides (i.e.front and rear edges 32, 34 of the beam), and grip it along its length.The claws may run around the entire perimeter of the wiper blade (notshown), or as shown in FIGS. 3 & 10, the claws may end in the vicinityof the outer ends of the cover. Additionally, securing structures, suchas detents or securing cavities (28) may be provided on the outer endsof the cover 22 which grip and secure the ends of the beam 80.Optionally, cover 22 can be provided with an interior recess to receivean upper portion of wiper strip 48 and further secure the cover alongits entire or a portion of its length. These and other methods ofattaching a cover 22 to the surface of a beam 80 may be used and areconsidered within the scope of the invention. The cover 22 may be madeof any suitable material, including natural or synthetic rubber orplastic or any other suitable polymeric material.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting, and that it be understood that it isthe following claims, including all equivalents, that are intended todefine the spirit and scope of this invention.

We claim:
 1. A wiper blade having two ends, two longitudinal sides, a top side, and a bottom side, the wiper blade comprising: a cover disposed on the top side of the wiper blade, the cover having two longitudinal sides, two outer ends and a top surface, wherein the cover is disposed on the top side of the wiper blade; the top surface of the cover has a base portion having a height and a raised portion having a height wherein the height of the raised portion is greater than the height of the base portion; the height of the raised portion gradually decreases as the raised portion approaches the outer ends of the cover; and wherein the raised portion has an apex that merges with the base portion before the outer ends of the cover such that multiple cross-sections of the top surface of the cover have a substantially geometrically similar cross-sectional profile along a length of a longitudinal axis that is parallel to the two longitudinal sides of the cover until the apex merges with the base portion, and wherein the base portion has a substantially constant height.
 2. The wiper blade of claim 1 wherein the raised portion forms a wind deflection structure having a generally triangular shape when viewed in cross section.
 3. The wiper blade of claim 1 wherein the cover is symmetric in shape across a plane that is transverse to the two longitudinal sides of the cover.
 4. The wiper blade of claim 1 wherein the cover is symmetric in shape across a plane that extends vertically through a longitudinal axis of the cover.
 5. The wiper blade of claim 1 wherein the cover is a unitary structure and is provided with a hole to accommodate a central bridge of the wiper blade.
 6. The wiper blade of claim 1 wherein the cover comprises two sections, each section having an inner end, wherein a gap is provided between the inner ends of the two sections to accommodate a central bridge of the wiper blade.
 7. The wiper blade of claim 6 wherein a cap is provided that covers the gap and the inner ends of the two sections.
 8. A wiper blade cover comprising two longitudinal sides, two outer ends and a top surface; wherein: the cover is capable of being disposed on the top side of a wiper blade, the wiper blade having two ends, two longitudinal sides, a top side, and a bottom side; the top surface of the cover has a base portion having a height and a raised portion having a height wherein the height of the raised portion is greater than the height of the base portion; the height of the raised portion gradually decreases as the raised portion approaches the outer ends of the cover; and wherein the raised portion has an apex that merges with the base portion before the outer ends of the cover such that multiple cross-sections of the top surface of the cover have a substantially geometrically similar cross-sectional profile along a length of a longitudinal axis that is parallel to the two longitudinal sides of the cover until the apex merges with the base portion, and wherein the base portion has a substantially constant height.
 9. The wiper blade cover of claim 8 wherein the raised portion forms a wind deflection structure having a generally triangular shape when viewed in cross-section.
 10. The wiper blade cover of claim 8 wherein the cover is symmetric in shape across a plane that is transverse to the two longitudinal sides of the cover.
 11. The wiper blade cover of claim 8 wherein the cover is a unitary structure and is provided with a hole to accommodate a central bridge of the wiper blade.
 12. The wiper blade cover of claim 8 wherein the cover comprises two sections, each section having an inner end, wherein a gap is provided between the inner ends of the two sections to accommodate a central bridge of the wiper blade.
 13. The wiper blade cover of claim 12 wherein the cover further comprises a cap that covers the gap and the inner ends of the two sections. 